Hull extension

Good stuff Billy..... Looks like the heighth and thickness of the motor mount section are lower than should be....and, possibly thinner than the original transom thickness?? You more than likely have both of these covered for sure. I think this is a great stab at improving your boat the way you want... Go slow with the chainsaw....unless you are going under....grin. You might not get this 100% the 1st try... and it is like you said.... something you saw at the show....and are willing to try. If it fails, you can say "Well I tried....and think this might work better.... or....This is great...I am glad I tried it.... :idea ", but... for sure... you will not have to sit on your boat with that endless stare wondering..... "Well....if I had only had the "parts" :oops: to try it...." Good job... :thup :thup Keep us posted.

Who knows what might happen to the last CD-18A built in 1984... Hummm

Byrdman...
 
Byrdman,
Thanks for the vote of confidence! If this turns out to be a mistake, it will just be my latest, not my first and I'm having fun. Hopefully some of you are having fun with me even if you might be laughing.
The height and thickness of the new transom is identical to original, must just be camera angle.

Bill
 
Sounds like it's time for my favorite quote from my favorite man...

"It is not the critic who counts; not the man who points out how the strong man stumbles, or where the doer of deeds could have done them better. The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood; who strives valiantly; who errs, and comes short again and again, because there is no effort without error and shortcoming; but who does actually strive to do the deeds; who knows the great enthusiasms, the great devotions; who spends himself in a worthy cause; who at the best knows in the end the triumph of high achievement, and who at the worst, if he fails, at least fails while daring greatly, so that his place shall never be with those cold and timid souls who know neither victory nor defeat."

Theodore Roosevelt
April 23, 1910
 
416: OK.... I love that!!! Going to cut-n-paste, laminate, and put in the cab of the plant truck as to carry me thru the season.... Forget any ED medications.... :oops: that is GREAT!!!
 
Billy,

I really appreciate that you are experimenting with YOUR 22 cruiser!! :wink

I don't know if I would be brave enough to try an extension on my own boat first! :sad

I have thought and wondered about how such a project would work out. Now I can wait for your report. :smilep
 
LunaC. If I had a shop that big, I'm sure I'd fill it with junk and not have room for this project anyway. No, I toyed with the idea of doing it but in the end I'm glad I didn't. When my bride and I went in to talk to the guy who is doing it, my wife's eyes instantly got irritated from the fiberglass dust. And I was going to do this in my attached garage...? a narrow escape indeed.
No the guy that is doing it, is a third generation fiberglasser and will get the job done faster and no doubt nicer than I could have done it.
Bill
 
Billy; I like the concept. How have you determined the mounting height of your engine? Do you just match what is existing based on your added bouency or is there a magic formula to determine the height? I've got a 1981 22' classic with a smaller motor well and think that I will eventually just square off the transom and put a bracket on. This will open up the entire cockpit, a big plus. I think you are really on to something here. Good work !!
Jimbo
 
Jimbo,
I didn't figure that adding the 18" would change things to the point of needing to alter engine height anymore than what I have on the engine's mounting bracket, if at all. I think (hope) that if a change is necessary that those adjustment holes will do the trick. One of the other alterations I'm hoping to do this year is to move the fresh water tank forward under the forward seat to also help shift some weight forward. That may be necessary to offset the engine being farther back. I don't know. That's been on my list for some time but I think I'll wait until after sea trials first.
So to answer your question, I just copied the original.
Bill
 
New pics in the album showing the additions all glassed on. Should be gel coating in the next few days. Also shows the hatch cover that needed to be put in so that glass attachment was possible.

Bill
 
That is cool Bill , nice work , my dad always told me never let fear and common sense stop you, go for it ! This is going to be a mean fishing machine. When I go prawning and pick my pots up in the afternoon , it is kind of annoying when the waves hit the transom and get all that water in the cockpit . Love my C-Dory but sometime I am thinking about trading it for the new CC , which has a closed transom. I also find that the water does not drain good back there, with all the hoses and cables, those drain holes need redesign.
Be a lot cheaper with your extension than a trade in ! Keep us updated . Hope I have the chance to meet you one day, we would love to make a trip to AK when Sharon retires next year?

Gary SEARAM
 
Ok. There was some question as to what the net effect this extension might have on the stern weight and the resultant handling. Rightfully so, fact is I'm still not sure. I think that the majority of those that questioned the wisdom of this felt that because I was moving weight aft that I would realize little benefit or worse, added relative weight to the aft.
I did some number crunching on the new extension similar to weight and balance calculations that are done on aircraft, and here is what I got.
These are the givens:
I assume that the original designers felt good about a 70 hp, 2 stroke Johnson, (approx. 270 lbs) and 36 gallons of fuel (216 lbs)
I also assumed that the center of gravity on a 22' Cruiser was the aft cabin wall. This gives us our base line for change but the CG doesn't have to be there to get a representative figure for changes to weight at the transom.
Using these as our facts, the Relative Weight at the transom,as originally designed was approx. 458 lbs.
Now then, I wanted to add (and did) a Yamaha 90 hp 4 stroke at approx. 370 lbs., and a total of 70 gallons of fuel (in the original fuel tank space) which would make for a Relative Weight at the transom of 735 lbs.
This seemed like a lot. It also seemed like it would take a lot to overcome, even with larger trim tabs. I feel like drag would have increased and efficiencey would have suffered too much.
So what happens when you add 18" to the hull in the configuration that I chose, with the motor and fuel capacity improvements that I want.
The net, using these assumptions are a Relative Weight at the transom of 450 lbs. 8 lbs less that the original design (all other things remaining equal)
All of this is based on best guesses.
If the actual CG is 20" farther forward for example, the difference increases to 60+ lbs at the transom. Within reason to me.
Coming home with 1/3 of 36 gallons vs. 1/3 of 70 gallons is a difference of +135 lbs. which may require shifting one of those Ice chests aft. Again, shifting weight is a matter of routine for boaters.
Longer hull, more drag...yes.
The biggest question I have is what will the effect be of the trim tab "pockets" on each aft side in a following sea.
I would be cool if the claims that the bracket manufacturers make came true... faster on plane, better handling, better fuel economy, higher speeds. The fact is, I won't know until I get there.

I would be glad to provide my calc's to anyone who asked, just give me a PM.

Bill
 
Gary on the SeaRam,
Don't buy the CC yet!!! What if this works? It seems like this would be a lot cheaper and maybe even better with the new fishwell.., if it works. That CC is answering a lot of the shortcomings of the CDory, but I wouldn't trade mine off, I'll just change it, and if I survive my imagination, let us know if you're coming up we'll try to get together. I've already got "wish I'd done that" changes to my own design, stay tuned.

Bill
 
Any guess as to when it will be done and on the water? I've been looking at the idea of a bracket since I bought the boat. I'm really interested in how yours' will handle. Only difference is I am looking at the idea of cutting out the old motor well and making a space for a cooler seat in the back. As a diver, it would make for a bit easier step over the transom. A couple of more feet of useable deck space for a lot less than stepping up to a bigger boat is appealing.
Norm
 
Norm, My best guess is about 3 weeks before getting it wet. Another week at the shop and I have to re-mount and re-rig it, adding another axle to the trailer too. Then I have this pesky thing called a job which keeps interfering with my boating. Of course, weather can still be a big factor this time of year for us too, so it could be awhile.
On your project, is the splashwell part of the reinforcement for the transom and if so, is that partly the function of the new seat? Sounds like a good idea and I'll sure let you all know if I've goofed.

Bill

Bluecrab, great article, I hadn't seen that one. My project isn't like a bracket in that it continues the hull rather than raises above it, so I probably won't realize many of the advantages of a bracket. I think the main advantage I will get will be in added displacement for my extra weight.
 
Bill;

I have been following this thread with great interest. I have a 16’ Cruiser that is over crowded and overloaded. Until I saw what you are doing, I thought my only solution was a larger boat. If your design works out like you anticipate, I will seriously consider doing the same to my boat. I have done a lot of modifications and projects to Miss”T” but not anywhere to the extent of yours.
 
Dave,
If this turns out to be something you'd like to do, contact me again when you've decided and I'll give you all of the info I have. I have more early fabrication pictures that you might like to see if that time comes, that shows how they mocked it up. Details that might save you time if you're doing it yourself.

Bill
 
Bill, I'm by no means a marine architect or engineer but just by looking at it I would guess that the current motor well does add at least some lateral rigidity to the aft end of the boat. I do figure that if I cut it out that I will run the vertical surfaces on each sie down to the deck and tie in with some form of fiberglass knee braces to the deck and transom. I e-mailed the owners of haileighs comet some time ago and asked if they had to add any additional bracing to the transom. The answer was no. Also spent a bit of time talking to Les @ EQ the other day when I was picking up my new motor. He pointed out that the bracket actually spreads the load on the transom out over a larger area (Duh! the obvious escaped me till it was pointed out) I did notice that yours is more of a hull extension than a bracket. I fortunately do not have the same weight issues. My Etec is in the same weight range as the original 2 strokes this boat was designed for. And actually moving my fuel fwd to saddle tanks will make it less of an issue. I'm just looking for enough flotation in the bracket to support itself and the slight additional moment of moving the motors aft. I should be able to go with a more conventional tapered bracket which will enable me to raise the motor a couple of notches and decrease drag from the lower unit. Hope to get measurements done this week and sent off for bids from some of the bracket manufacturers. Then will await your test before I write the check. Hope it works out the way we all hope it does.
Norm
 
Back
Top